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Seems clear there are different thresholds between the 2 and 3. Since most tunes push the limiter up a few hundred, you will probably see a lot more above 3 on a tuned 2. TB993, looks like you got your money's worth on that tune! Blew past 205 with ease :-)
The engine has since been apart (diluted oil, bearing failure new crank etc) and there was no ill effects from these apparent over revs....
GT2s all seem to do that over rev "dance" when you change gear enthusiastically like in the vid below, I don't know if the engine is recording over revs here or its just the needle doing its thing ?
So you opened the engine because you were afraid that it would have damage from the overrevs - or because of a tuning on the engine?
I repeat what I already said numerous times:
- GT3: very difficult to get overrevs..at least 3,4..at 5 & 6 you must be a complete idiot - unless CUP Car
-GT2: very easy to get 3-4 - in fact 997 turbo has the same issue..
Is there no one who can confirm this as well ?- so owner who own GT3 and GT2..? There must be some out here..I don't want to be the only one here claiming this..
So you opened the engine because you were afraid that it would have damage from the overrevs - or because of a tuning on the engine?
Sorry, I wasn't very clear, engine was opened up because of damage which was caused by fuel dilution from faulty component connected with the tuning. It was nothing to do with the over rev readings or over rev damage.
So you opened the engine because you were afraid that it would have damage from the overrevs - or because of a tuning on the engine?
I repeat what I already said numerous times:
- GT3: very difficult to get overrevs..at least 3,4..at 5 & 6 you must be a complete idiot - unless CUP Car
-GT2: very easy to get 3-4 - in fact 997 turbo has the same issue..
Is there no one who can confirm this as well ?- so owner who own GT3 and GT2..? There must be some out here..I don't want to be the only one here claiming this..
I don't think range 4 is difficult to hit with a GT3, even range 5 can be hit with one mis-shift. It's not idiotic, but if it happens all the time, it is idiotic.
P_Collector - From all of the evidence I've seen on this, it seems clear that the 2 and 3 have different threshold parameters for recording over revs - either that or the rev limiting ignition cut off behaves differently on a 2 vs. 3 (perhaps different due to launch control parameters - who knows). The other thing to consider is that some folks have a tune (certainly a lot of the twin turbo guys you reference). Even the mildest software tune tends to push the red line up by 300-500 rpm. I suspect those with a tune would see significantly more and higher ranges. So, probably tough to get good data unless the baseline comes from bone stock cars and some degree of certainty that no downshifts have ever occurred above the redline (even a little above). For instance, on my GT2, I can say with certainty that a) it is bone stock, b) I have bounced the rev limiter several times on up shift and c) I have never had a downshift that resulted in RPM exceeding 5000 (well below rev limit). That's as much feedback as I can provide on mine. Hope that helps.
Also, there is a latency to process and cutoff ignition (albeit measured in milliseconds I'm sure). The GT2 and TT are so explosive to the red line in 1st and 2nd compare to NA, that it could account for deltas between the numbers we see on a 2 vs. 3 before the limiter can actually cutoff the engine. Anyway, I digress into the theoretical without any facts whatsoever - but it seems reasonable :-)
Nobody is a moron if the technology you use fails you- in my case the stupid DEM's wore out from track use, and with sloppy engine mounts it's easy to get a miss-shift when driving at 10/10! When something like your engine mounts wear out, it happens slowly and you start to question many things, like linkage and cables or perhaps failing synchro's, no, no, no. You go through a round of upgrades but still not ideal, and it happens again! ****e! WTF! You try solid engine mounts, what a revelation! Never happens again. The moron part is in believing Porsche hype about how great the DEM are, so the rest of you learn from my mistake.
Now, regarding what happens to the Metzger on overrevs range 5, absolutely nothing. My car was stronger 50 hours after the two events as evidence by trap speed at my regular track then before. Also to consider is the amount of time you spend there in Range 5- in my case each time was like 30 ignitions at which is around a tenth of a second at that RPM. Really nothing at all when in the cup application they bang downshifts and touch 9 grand on a regular basis. Two top Porsche engine builders weighed in on this for me and while they both said they would love to take my money on a rebuild, don't worry, just drive it. Leakdown tests and boroscope showed nothing at all wrong.
Now, running this up the flagpole with Porsche is a different story. There is absolutely no way to remove an overrev from warranty consideration except for a complete engine replacement. NOT a rebuild by a dealer, bottom end, top end or otherwise. REALLY? Yes really. The short answer, we can never be sure that your overrevs didnt cause distortion of your engine block or other problems. How much is a new engine then- $55,000. See ya.
As much as I loved shifting, and do regularly in my Spec Racer and other cars (with no miss-shifts!), I for one am glad that my new inbound GT3 can only overrev if it's a fault of the car and therefore covered under warranty.
I don't think hitting it once qualifies as being moronic.
In a bog standard GT2, torque drops quite a bit, significantly before redline. Like, a thousand rpm or so. So you effectively have some overrev. People complain about the tach needle jumping around but if you drive it with any care you'll never really come close to the redline. Even with my 68mm VTG turbos and 3.8l overbore, AND raised redline, I don't have any significant range 4, let alone 5 or 6 which are 0.
As for the rest, it sounds more like a maintenance issue than driver issue.
Originally Posted by montoya
^ You haven't lived until you hit Range 5!
Nobody is a moron if the technology you use fails you- in my case the stupid DEM's wore out from track use, and with sloppy engine mounts it's easy to get a miss-shift when driving at 10/10! When something like your engine mounts wear out, it happens slowly and you start to question many things, like linkage and cables or perhaps failing synchro's, no, no, no. You go through a round of upgrades but still not ideal, and it happens again! ****e! WTF! You try solid engine mounts, what a revelation! Never happens again. The moron part is in believing Porsche hype about how great the DEM are, so the rest of you learn from my mistake.
Now, regarding what happens to the Metzger on overrevs range 5, absolutely nothing. My car was stronger 50 hours after the two events as evidence by trap speed at my regular track then before. Also to consider is the amount of time you spend there in Range 5- in my case each time was like 30 ignitions at which is around a tenth of a second at that RPM. Really nothing at all when in the cup application they bang downshifts and touch 9 grand on a regular basis. Two top Porsche engine builders weighed in on this for me and while they both said they would love to take my money on a rebuild, don't worry, just drive it. Leakdown tests and boroscope showed nothing at all wrong.
Now, running this up the flagpole with Porsche is a different story. There is absolutely no way to remove an overrev from warranty consideration except for a complete engine replacement. NOT a rebuild by a dealer, bottom end, top end or otherwise. REALLY? Yes really. The short answer, we can never be sure that your overrevs didnt cause distortion of your engine block or other problems. How much is a new engine then- $55,000. See ya.
As much as I loved shifting, and do regularly in my Spec Racer and other cars (with no miss-shifts!), I for one am glad that my new inbound GT3 can only overrev if it's a fault of the car and therefore covered under warranty.
Number of ignitions range 1 33573 / 346.1h
Number of ignitions range 2 11036 / 346h
Number of ignitions range 3 2474 / 346h
Number of ignitions range 4 173 / 345.8h
Number of ignitions range 5 0 / 0h
Number of ignitions range 6 0 / 0h
Operating hours counter 346.2
Almost certainly from driving on the track and hitting the limiter.
I've had zero problems with the car (knock on wood).
Attached are the rev ranges I got from a service tech, for reference.
Thing that I noticed is a R4 overrev on a GT2/Turbo is 7400-7900 RPM. On a GT3 it's 9600-10000 RPM. Same block, different internals, I know. But, for some reason I think a R4 on a GT2/Turbo is less ... dangerous ... than on a higher revving engine. But, there's no real technical basis in my opinion. Please correct me if I am way off.
Anyway, I am not too concerned, though I know someone looking to buy the car in the future might balk.
This is mine as of three days ago. I drive my car HARD on slow tracks, easy on big ones.
Bought it with about 200 hours and less than 1100 miles on it (a lot of traffic?). Even with a raised limiter to 7400rpm (3.8l overbore with revised valve train and bottom end windage improvements) it is not far off from stock profile (stock cams) which means power dropoff far before 7400, more like 6000, so I have 1500rpm over rev capability (which I have yet to use because I don't have any reason- street cars on tracks are not going to be fast). On my 109 octane DME I haven't even seen upper limits.
Recently, I was looking at a white '08 GT2 up in the Chicago vicinity, which the dealer's sales associate represented as having never been tracked, and so pristine that they didn't feel the need to get a VAL (DME) report run on it when they took it in trade. (Or words to that effect)
I had my Porsche dealer run the VIN to see if there'd been a DME run on the car, which has ~23,000 miles (and certainly looks beautiful in the pictures...). A report from 2011 came up, back when the car had about 13K miles.
Range 1: 35,834
Range 2: 14,195
Range 3: 2971
Range 4: 175
Range 5: 0
Range 6: 0
I don't know how many hours since the range 3's or 4's, and the report is 3 years old, so clearly a new PPI w/DME(VAL) needs to be run, but this certainly doesn't seem indicative of a car that's been babied, and never tracked. Does it?
Recently, I was looking at a white '08 GT2 up in the Chicago vicinity, which the dealer's sales associate represented as having never been tracked, and so pristine that they didn't feel the need to get a VAL (DME) report run on it when they took it in trade. (Or words to that effect)
I had my Porsche dealer run the VIN to see if there'd been a DME run on the car, which has ~23,000 miles (and certainly looks beautiful in the pictures...). A report from 2011 came up, back when the car had about 13K miles.
Range 1: 35,834
Range 2: 14,195
Range 3: 2971
Range 4: 175
Range 5: 0
Range 6: 0
I don't know how many hours since the range 3's or 4's, and the report is 3 years old, so clearly a new PPI w/DME(VAL) needs to be run, but this certainly doesn't seem indicative of a car that's been babied, and never tracked. Does it?
Based on what I've seen, it's easy for a non-tracked GT2 to have a *very low* number of range 4's. This isn't the GT3 engine, this one hits 3's and 4's really easily.
So, I suppose I'd say that based on the data you provided, I can't conclude one way or another regarding whether or not this car has been tracked.
Based on what I've learned on this thread , I concur that those over-rev counts don't look bad to me. Whether it's been tracked or not, or what the counts are right now... unknown/TBD.
11-10-2014, 08:39 AM
